2-Chlorodeoxyadenosine (2-CdA) will be used to treat for a circulating autoantibody which may be responsible for disease. Included are patients with cryoglobulins where cold insoluble antibody may damage skin, kidneys, nerves and other organs. Another group may have antibodies directed against neural proteins and gangliosides, leading to sensory-motor neuropathies. The study will determine whether such patients will respond to 2-CdA.